Stripper for collapsible tube forming machines



March 7, 1933. w US 1,900,666

STRIPPER FOR COLLAPSIBLE TUBE FORMING MACHINES Filed Feb. 11, 1951 Fig-1 N l Jag- :2 g-' 30 INVENTOR I 121a! fer Prussmg' Patented Mar. 7, 19 33 um'rso STATES PATENT OFFICE wAL'rsa raussnto, or nnooxmm, new roan, ABSIGNOB 'ro vrc'ro'n mirAL rnomrc'rs oonroaarrox, or. snooxmm, NEW YORK, A CORPORATION or new Yonx STIR/ZIPPER FOB OOLLAPSIBLE TUBE FOBIING momma Application sued February 11, 1931. Serial in. 514,985.

This invention relates to machines which operate to extrude or squeeze comparatively thick metal blanks or slugs into thin collapsible tubes such as are used for tooth-paste, shaving cream, and the like.

My invention relates, particularly, to means for removin or stripping the collapsible tube forme by the machine, from the male die, by which the tube is earned after it has been extruded. The means for feeding the metal blanks, discs or slugs into the female die, preparatory to the extruding operation by the male die, is illustrated in m co-pending application for patent for extru ing machine, Serial No. 336,868, filed Jan.- uary 21st, 1929, and hence need not be further shown nor described. The structure of the female die is adequately disclosed in my 00-. pending ap lication for patent for die for extrudin col a sible tubes, filed February 4th, 1931, erial be shown nor descri d in detail.

Said co-pending applications rthermore disclose how the comparatively thick metal disc is changed into a thin walled collapsible 4 tube by the extruding operation, when the end of the male die squeezes the blank into the female die and thereby causes the comparatively soft metal of the blank to flow or uirt suddenly upwardly about the male die. aid co-pending a plications furthermore disclose, that as t e male die is withdrawn from the female die, the extruded tube remains on the male die and is carried out of the female die thereby. My co-pending application for patent for extruding machine further discloses that the tube thus extruded may be dislcfliarged from the male die by means of an air ast.

I have found, however, that when the blanks are made of certain metals such as aluminum, the extruded tube made of such metal cannot efiectively be removed at the proper time from the male die by a blast of air or the like. Should the tube remain on the die due to the failure of the stripping mechanism to function properly, further operation of the machine in its attempt to extrude another tube, may cause serious damage to o. 513 93, and hence need not;

therefore contemplates the provision of simple and efficient mechanical means for engagmg and stripping such tubes from the ma o die automatically, and preparatory to the extrusion of the succeeding tube. My invention further contemplates the provision of such positively acting stripping means, which is yie dable to conform automatically to the varying diameters of the male die as it is moved in properly timed relation to said die and which is further so designed as to push upon the end of the tube and to overcome the friction between the tube and the die to insure that the tube is stripped from the die at the proper time.

, The various objects of my invention will be clear from the description which follows, and from the drawing, in which,

Fig. 1 is a front elevation of a typical extrudlng ress to which my new tu stri ping mec anism has been applied, said mec anism bei shown arranged at a point between the imits of the vertical movement thereof. i

Fig. 2 is a top plan view and 1partial section, taken-on the line 22 of ig. 1, of a portion of the bed and frame of the machine, and of the tube stripping mechanism.

Fig. 3 is a bottom plan view of the yieldable strfipping plates. Y

ig. 4 is a side elevation of part of the machine, showing, particularly the means for actuating the strippin mechanism, and

Fig. 5 is a vertical section of part of the male die and of the stripping plates as they appear during the stripping operation.

In that practical embodiment of my invention which I have illustrated by way of example, the machine for extruding the blanks into collapsible tubes consists of a frame 10, having abed 11 on which the female die 12 is removabl secured, as by means of the bolster 13 and t e nuts 14. The male die 15 is reciprocated vertically through a comparatively short distance for squeezing the disc into the female die. Said male die is further oscillated about a vertical axis toward and from the female die, to bring it alternately, into stripping position and into the dies or to the machine. My invention extruding position.

The mechanism illustrated for carr ing out this purpose consists of the main s iaft 16, which carries the fly wheel 17 at one end and which operates the toggles 18 and 19. Said toggles. in turn reciprocate the cross head 20, which in turn carries the reciprocatory and oscillatory hollow shaft 21-to which is secured the arm 22 movable with the shaft. The mechanism for causing oscillation of the shaft 21 and consequently of the male die 15 operatively connected thereto, may include a pin 23 on the shaft 21, operating in a suita le cam groove 24 in the stationary cam 25. The male die 15 is carried by the arm 22 and is given an oscillatory movement as well as a vertical movement at the roper time, the cam groove 24 being suita ly shaped for that purpose. In other words, the male die 15 is oscillated toward the front of the machine, after the tube has been extruded thereon into a position wherein the tube maybe conveniently stripped therefrom. This position at the front of the machine I will term the stripping position (Figs. 1 and 2).

In order to extrude the blank fed to the female die 12 into a collapsible tube 26 formed about the male die, said die is first oscillated into axial alignment with the female die by the mechanism above described, and is then given a slight vertical movement sufiicient to s ueeze the metal blank against the suitably s aped walls of the female die. The metal so squeezed can flow only upwardly out of the female die and forms the thin walled tube 26 arranged about and carried by the male die.

In order to determine the diameter of the innermost wall 27 of the tube thus extruded and to maintain the wall of the tube out of contact, in so far as possible, with the male die, said die is slightly enlarged near its lower end as at 28, the corner or rim 29 acting as an obstruction past which the metal of the blank flows during the extruding operation, and thereby determining the diameter of the wall 27 of the tube. The conical portion 30 of the die forms the usual conical portion of the collapsible tube in connection with a similarly shaped part of the female die, while the teat 31 forms the neck of the tube in cooperation with the female die. It will be understood that the teat 31 may be made of a separate piece or in one piece with the remainder of the die for the purpose of forming a closed or an open end on the collapsible tube, as may be desired.

The tube 26, when formed on the die 15, is frictionally held thereon by its frictional engagement with the corner or rim 29. It therefore becomes necessary to overcome said frictional engagement, so that the formed tube may be removed from the die 15 preable and impractical for this parator for the operation of the extrusion of anot er tube.

In the case where the tubes are formed of blanks made of tin, lead or alloys of such comparatively soft metals, the die 15 is provided with an opening therethrough, and a blast of air acting against the closed end of the tube is usually operative to strip the tube from the die. In the case, however, of harder metals such as aluminum, I have found that the use of an air blast is uncertain, undependui ose. The tube 26,-when made of such ardbr metals, seems to engage the die more firmly and to offer greater resistance to its removal from the die. I have-therefore found it advisable to use a more positive means for stri ping the tube from the die, which means wi I now be described.

A pair of plates 35 and 36, each having a substantially semi-circular opening therethrough, as 37 and 38 respectively, are arranged about the male die 15. The plates 35 and 36 are further arranged edge to edge with the respective edges 39 and 40 thereof normally in contact, and the lower surfaces thereof lying in the same plane.-. The male die 15 is inserted through the openings 37 and 38, which openings communicate with each other and in the osition illustrated in Fig. 3, form a circle, t e diameter of which is slightly greater than that of the upper or cylindrical portion of the-die 15. To permit t e plates 35 and 36 to be moved relativel to and coaxially of the die'to a position ad jacent the' rim-29, said plates are yieldably and separably connected to each other.

For this purpose, a pair of pins as 41 and 42 project downwardly from the plate 35, and a similar pair of pins 43 and 44 similarl project downwardly from the plate 36. X tension spring 45 connects the pins 41 and 43 while a similar spring 46 connects the pins 42 and 44.

The adjacent ed cs 39 and 40 of said plates are thereby normally held in cont-act, but the plates nevertheless are yieldable transversely and separable relatively to each other, on the application of radial outward pressure against the walls of the openings 37 and 38. Such pressure occurs when the plates are moved downwardly along the die 15 to the enlarged portion 28. Said plates are so moved downwardly alon the die 15 after said die has been oscillate into stripping position with the tubeformed thereon.

It will be seen that on the downward move ment of the plates, the under surfaces 47 thereof engage the end of the tube 26 whether said end is of regular or irregular shape, and exert positive downward pressure thereon, sufficient to overcome the frictional engagement of the inner wall of the tube with the rim 29. The downward movement of the plates is continued until said plates reach or stripped from the die. The bare die is then oscillated back into extruding plosition, carrying the plates with it while t e plates are being brought back upwardiy toward the uppermost part of the die out of the way of the next tube which is to be extruded upon the die.

The means for actuatin the stripping plates in timed relation to t e die and to the remainder of the machine may be operatively connected to any suitable moving part of the machine. In the operating connections illustrated as one suggested form of connection, the cam is secured to one end of the drive shaft 16, and engages the cam follower 51 secured at one end to the shaft 52. At the other end of said shaft is the forked lever 53 which engages and operates the reciprocating rod 54.

A spring as 55 connected to the upper end 56 of the rod and to a stationary point such as 57, serves to ur e said rod normally u wardly and to maintain the follower 51 in engagement with its cam 50. Suitable supports as 58 and 59 are secured to the frame 10 provide bearings and guides for the vertica reciprocation of the rod 54. A link, as 60, secured to said rod at one end, carries the collar 61 at its other end, said collar being slidable on the stationary rod 62 secured to the cam 25 and passing through the arm 22 and the shaft 21, and serving as a uide for said arm and shaft. Arranged on t e under face of the collar 61 is the supporting plate 63 for the stripping plates. An opening 64, arranged coaxially of and of greater diameter than the normal diameters of the openings 37 and 38 is made on the plate 63 for the reception of the die 15. A second collar as 65 cooperates with the collar 61 to hold the supporting late 63 therebetween, and is secured to the plate 63.

The stripping plates 35 and 36 are separably and movab y carried by the supporting plate 63 as by means of headed screws, rivets or other suitable fastening members 70, assing through transversely elongated slots 1 in the stripping plates, and secured to the supporting plate 63. It will be understood that any number of such slots 71 and fastening guide members may be used, and arranged at the proper points to allow the stripping plates to yield as they are moved against the enlarged portion of the die.

It will further be understood that the operating mechanism for reciprocating the stripping p'ates is synchronized with the operation of the die 15, and that said plates may oscillate with the die 15 on the movement of said die from the stripping to the extruding position and back again. The movement of the stripping plates is further so timed that they will complete their downward stri ping movement to strip the tube from the ie, only after the die 15 has reached the stripping position, and that the complete their upward movement out of t e way of the tube extruded on the die before said die reaches its lowermost extruding positions.

It will be seen that I have provided simple and efiicient means designed to be quickly and easily assembled on or removed from a male die, for stripping a tube resistant to such stripping action, fromthe die on which the tube is extruded, which means is positive in its action, so that the tube does not remain on the die and thereby present a source of possible damage to the machine. It will further be understood that while I have shown and described certain specific embodiments of m invention, I do not intend to limit myse f thereto but intend toclaim m invention as broadly as may be permitted y the state of the prior art and the terms of the appended claims.

I claim:

1. In combination with the male die of a collapsible tube extruding machine, means for extruding a tube on to and around the die, a plate having an openin through which the die is passed, and means or reciprocating the plate relatively to the die to carry said plate into engagement with the open end 0 the tube carried by the die and to push the tube past the point of engagement thereof with the die to strip the tube from the die, said reciprocating means comprisin a reciprocating springulled rod, a mem r connecting the god an the plate and a guide for the mem- 2. In a machine for extruding blanks into collapsible tubes, a tube-extruding die having an enlarged portion adapted to extrude a tube thereon in outwardly spaced relation to the remainder of the die surface, a plate movable with said die and having a horizontal surface terminating about an aperture adjacent the surface of the die, and maintained out of contact with the tube surface, and spaced slightly therefrom, and means for moving the plate relativel to and in the direction of the axis of the die whereby the plate surface engages and pushes only upon the end of a tube extiruded on the die to strip the tube from the 3. Tube stripping means for collapsible tube forming machines comprising a supporting plate having an aperture therein. a pair of similar plates slidable laterally and bodily toward and from each other and carried by a supporting plate and slightly overhanging the aperture, and means for moving the plate into postion beyond the tube formed by the machine and for then moving the pair of plates to push vertically only against the end of the tube.

4. In a collapsible tube forming machine, means for extruding a tube including a substantially cylindrical male die having an enlarged portion near one end thereof, and

means for stripping the extruded tube from the die comprising a pair of smnlarmembers,

each having a semi-circular 0 .ning therein for the passage of the die an movable as a unit'relativel to the die for pushing on the 0 )en end of t 1e tube, and a spring for ieldably connecting the members and permitting separation thereof whenthe members engage into edge abutting relation, means for supporting said plates, said plates being separated bodily on the engagement of the walls of the openings with the enlarged portion of the die, and means includinga spring-pulled rod for reciprocating the plates relatively to the die.

6. A stripper for removing thin collapsible tubes from a die on which such tubes are formed and retained, comprising a reciprocatory supporting plate having an opening therein for the passage of a die, a pair of similar plates each having part of an opening therein of less diameter than the opening of the support, and thereby overhanging the opening of the support, and having laterally elongated guide slots therein, springs normally maintaining the plates in yieldable edge abutting relation, and headed members carried by the support and passing through the slots'of the plates and adapted to permit lateral bodily movement of the similar plates away from each other and against the action of the springs.

7. A stripper for removing a thin collapsible tube from a substantially cylindrical sup port therefor having an enlarged portion, comprising a pair of similar members each having a wall surrounding an aperture therein and'having an end surface terminating at said walland adapted to push upon the end of a tube, and resilient means normally urging the members toward each other and permitting slight separation of said members when the enlarged portion of the support engages 'the walls of the members.

8. In a collapsible tube forming machine, a male die adapted to engage and retain a tube extruded on said die, and means for removing the extruded tube from the die comprising a member having a substantially flat under surface adapted to engage and push upon the end only of the tube, said surface extending close to the surface of the die and extending outwardly therefrom a substantial distance in all directions and means for reciprocating the member relatively to the die.

9. In a collapsible tube forming machine, a die for extruding a blank into a tube and for retaining the tube thereon until stripped therefrom, and a member movable along the die and adapted to engage and ush u )on the bent end of the tube only, regar less o the irregularity of said end to strip the tube from the die, said member being arranged above and out of contact at all times with the cylindrical surface of the tube.

10. In a machine for extruding collapsible tubes, a reciprocatory male extrudin die, a pair of transversely aligned and re atively yieldable plates each provided with an openmg through which the die is inserted, and

means for reciprocating the plates relatively to the die to strip an extruded tube from the die by engaging only the end of the tube.

WALTER PRUSSING.

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